Make \X accept both `\ ' and `\~', converting them to single space

characters.

* src/roff/troff/token.h (token): Add TOKEN_UNSTRETCHABLE_SPACE.
(token::unstretchable_space): New inline function.
* src/roff/troff/input.cc (token::next, token::delimiter,
token::description, token::add_to_node_list, token::process): Handle
TOKEN_UNSTRETCHABLE_NODE.
(encode_char): Handle tok.stretchable_space and
tok.unstretchable_space.

* NEWS, doc/groff.texinfo: Document it..

5 files changed, 41 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index ad09ae9c..331c9606 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2002-06-20  Werner LEMBERG  <wl@gnu.org>
+
+	Make \X accept both `\ ' and `\~', converting them to single space
+	characters.
+
+	* src/roff/troff/token.h (token): Add TOKEN_UNSTRETCHABLE_SPACE.
+	(token::unstretchable_space): New inline function.
+	* src/roff/troff/input.cc (token::next, token::delimiter,
+	token::description, token::add_to_node_list, token::process): Handle
+	TOKEN_UNSTRETCHABLE_NODE.
+	(encode_char): Handle tok.stretchable_space and
+	tok.unstretchable_space.
+
+	* NEWS, doc/groff.texinfo: Document it..
+
 2002-06-19  Werner LEMBERG  <wl@gnu.org>
 
 	* src/devices/grops/ps.cc (ps_printer::special): Fix error message.
diff --git a/NEWS b/NEWS
index cc1bac1c..0b09a895 100644
--- a/NEWS
+++ b/NEWS
@@ -150,7 +150,8 @@ o A new escape sequence `\O' is available to disable and enable glyph
   output.  Please see groff_diff.7 and groff.texinfo for more details.
 
 o The escapes `\%', `\&', `\)', and `\:' no longer cause an error in \X;
-  they are ignored now.
+  they are ignored now.  Additionally `\ ' and `\~' are converted to
+  single space characters.
 
 o The default tab distance in nroff mode is now 0.8i to be compatible
   with UNIX troff.
diff --git a/doc/groff.texinfo b/doc/groff.texinfo
index 05a44874..392fc4d4 100644
--- a/doc/groff.texinfo
+++ b/doc/groff.texinfo
@@ -6752,7 +6752,7 @@ Internals}, for more on this process).
 @DefreqListEnd {trin, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}}
 Translate character @var{a} to glyph@w{ }@var{b}, character @var{c} to
 glyph@w{ }@var{d}, etc.  If there is an odd number of arguments, the
-last one is translated to an unstretchable space (@samp{\ }).
+last one is translated to an unstretchable space (@w{@samp{\ }}).
 
 The @code{trin} request is identical to @code{tr},
 but when you unformat a diversion with @code{asciify}
@@ -11611,7 +11611,8 @@ output preceded with @w{@samp{x X}}.
 @cindex @code{\@r{<colon>}}, in @code{\X}
 @end ifinfo
 The escapes @code{\&}, @code{\)}, @code{\%}, and @code{\:} are ignored
-within @code{\X}; all other escapes (except @code{\\} which produces a
+within @code{\X}, @w{@samp{\ }} and @code{\~} are converted to single
+space characters.  All other escapes (except @code{\\} which produces a
 backslash) cause an error.
 
 @kindex use_charnames_in_special
diff --git a/src/roff/troff/input.cc b/src/roff/troff/input.cc
index f1b96d71..4df1fc55 100644
--- a/src/roff/troff/input.cc
+++ b/src/roff/troff/input.cc
@@ -1569,8 +1569,7 @@ void token::next()
 	return;
       case ESCAPE_SPACE:
       ESCAPE_SPACE:
-	type = TOKEN_NODE;
-	nd = new space_char_hmotion_node(curenv->get_space_width());
+	type = TOKEN_UNSTRETCHABLE_SPACE;
 	return;
       case ESCAPE_TILDE:
       ESCAPE_TILDE:
@@ -2097,6 +2096,7 @@ int token::delimiter(int err)
   case TOKEN_NODE:
   case TOKEN_SPACE:
   case TOKEN_STRETCHABLE_SPACE:
+  case TOKEN_UNSTRETCHABLE_SPACE:
   case TOKEN_TAB:
   case TOKEN_NEWLINE:
     if (err)
@@ -2151,6 +2151,8 @@ const char *token::description()
     return "`\\p'";
   case TOKEN_STRETCHABLE_SPACE:
     return "`\\~'";
+  case TOKEN_UNSTRETCHABLE_SPACE:
+    return "`\\ '";
   case TOKEN_TAB:
     return "a tab character";
   case TOKEN_TRANSPARENT:
@@ -4610,6 +4612,9 @@ static void encode_char(macro *mac, char c)
 	mac->append(')');
       }
     }
+    else if (tok.stretchable_space()
+	     || tok.unstretchable_space())
+      mac->append(' ');
     else if (!(tok.hyphen_indicator()
 	       || tok.dummy()
 	       || tok.transparent_dummy()
@@ -5949,6 +5954,9 @@ int token::add_to_node_list(node **pp)
   case TOKEN_STRETCHABLE_SPACE:
     n = new unbreakable_space_node(curenv->get_space_width());
     break;
+  case TOKEN_UNSTRETCHABLE_SPACE:
+    n = new space_char_hmotion_node(curenv->get_space_width());
+    break;
   case TOKEN_TRANSPARENT_DUMMY:
     n = new transparent_dummy_node;
     break;
@@ -6040,6 +6048,9 @@ void token::process()
   case TOKEN_STRETCHABLE_SPACE:
     curenv->add_node(new unbreakable_space_node(curenv->get_space_width()));
     break;
+  case TOKEN_UNSTRETCHABLE_SPACE:
+    curenv->add_node(new space_char_hmotion_node(curenv->get_space_width()));
+    break;
   case TOKEN_TAB:
     curenv->handle_tab(0);
     break;
diff --git a/src/roff/troff/token.h b/src/roff/troff/token.h
index 2f0c3ccc..59f2aa2d 100644
--- a/src/roff/troff/token.h
+++ b/src/roff/troff/token.h
@@ -51,9 +51,10 @@ class token {
     TOKEN_REQUEST,
     TOKEN_RIGHT_BRACE,
     TOKEN_SPACE,		// ` ' -- ordinary space
-    TOKEN_SPECIAL,		// a special character -- \' \` \- \(xx
+    TOKEN_SPECIAL,		// a special character -- \' \` \- \(xx \[xxx]
     TOKEN_SPREAD,		// \p -- break and spread output line 
     TOKEN_STRETCHABLE_SPACE,	// \~
+    TOKEN_UNSTRETCHABLE_SPACE,	// `\ '
     TOKEN_TAB,			// tab
     TOKEN_TRANSPARENT,		// \!
     TOKEN_TRANSPARENT_DUMMY,	// \)
@@ -72,6 +73,7 @@ public:
   int nspaces();		// 1 if space, 2 if double space, 0 otherwise
   int space();			// is the current token a space?
   int stretchable_space();	// is the current token a stretchable space?
+  int unstretchable_space();	// is the current token an unstretchable space?
   int white_space();		// is the current token space or tab?
   int special();		// is the current token a special character?
   int newline();		// is the current token a newline?
@@ -140,6 +142,11 @@ inline int token::stretchable_space()
   return type == TOKEN_STRETCHABLE_SPACE;
 }
 
+inline int token::unstretchable_space()
+{
+  return type == TOKEN_UNSTRETCHABLE_SPACE;
+}
+
 inline int token::special()
 { 
   return type == TOKEN_SPECIAL;